A hard disk drive (HDD) is a non-volatile storage device that is housed in a protective enclosure and stores digitally encoded data on one or more circular disks having magnetic surfaces. When an HDD is in operation, each magnetic-recording disk is rapidly rotated by a spindle system. Data is read from and written to a magnetic-recording disk using a read-write head that is positioned over a specific location of a disk by an actuator. A read-write head uses a magnetic field to read data from and write data to the surface of a magnetic-recording disk. A write head makes use of the electricity flowing through a coil, which produces a magnetic field. Electrical pulses are sent to the write head, with different patterns of positive and negative currents. The current in the coil of the write head induces a magnetic field across the gap between the head and the magnetic disk, which in turn magnetizes a small area on the recording medium.
Because the recording disks spin within an HDD during operation, gas flow is generated. Indeed, the air bearing slider (or, generally, gas beating slider) on which a read-write head is housed relies on such gas flow in order to fly over a disk in order to function as purposed. However, such gas flow generated within an HDD can have detrimental effects when impinging upon or interacting with he disk stack and the head stack assembly (HSA), such as by contributing to imparting unwanted flow induced vibration (FIV) upon the disks and/or HSA, for example. FIV can negatively impact head positioning accuracy thereby leading to track misregistration (TMR), which essentially refers to the mis-location of the read-write head relative to its desired location, of which there are numerous components. Hence, controlling the gas flow within an HDD is considered an ongoing design challenge. Furthermore, often the case may be that, in the overall HDD design, positively affecting the FIV associated with the disks or the HSA may negatively affect the FIV associated with the other.
Any approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.